diff options
Diffstat (limited to 'Documentation/fpga')
| -rw-r--r-- | Documentation/fpga/fpga-mgr.txt | 35 |
1 files changed, 26 insertions, 9 deletions
diff --git a/Documentation/fpga/fpga-mgr.txt b/Documentation/fpga/fpga-mgr.txt index 6ebc714f4b03..cc6413ed6fc9 100644 --- a/Documentation/fpga/fpga-mgr.txt +++ b/Documentation/fpga/fpga-mgr.txt @@ -48,8 +48,20 @@ To get/put a reference to a FPGA manager: struct fpga_manager *fpga_mgr_get(struct device *dev); void fpga_mgr_put(struct fpga_manager *mgr); -Given a DT node or device, get an exclusive reference to a FPGA manager. -fpga_mgr_put releases the reference. +Given a DT node or device, get a reference to a FPGA manager. This pointer +can be saved until you are ready to program the FPGA. fpga_mgr_put releases +the reference. + + +To get exclusive control of a FPGA manager: +------------------------------------------- + + int fpga_mgr_lock(struct fpga_manager *mgr); + void fpga_mgr_unlock(struct fpga_manager *mgr); + +The user should call fpga_mgr_lock and verify that it returns 0 before +attempting to program the FPGA. Likewise, the user should call +fpga_mgr_unlock when done programming the FPGA. To register or unregister the low level FPGA-specific driver: @@ -67,13 +79,21 @@ device." How to write an image buffer to a supported FPGA ================================================ -/* Include to get the API */ #include <linux/fpga/fpga-mgr.h> struct fpga_manager *mgr; struct fpga_image_info *info; int ret; +/* + * Get a reference to FPGA manager. The manager is not locked, so you can + * hold onto this reference without it preventing programming. + * + * This example uses the device node of the manager. Alternatively, use + * fpga_mgr_get(dev) instead if you have the device. + */ +mgr = of_fpga_mgr_get(mgr_node); + /* struct with information about the FPGA image to program. */ info = fpga_image_info_alloc(dev); @@ -99,17 +119,14 @@ if (image is in a scatter gather table) { } -/* - * Get a reference to FPGA manager. This example uses the device node of the - * manager. You could use fpga_mgr_get() instead if you have the device instead - * of the device node. - */ -mgr = of_fpga_mgr_get(mgr_node); +/* Get exclusive control of FPGA manager */ +ret = fpga_mgr_lock(mgr); /* Load the buffer to the FPGA */ ret = fpga_mgr_buf_load(mgr, &info, buf, count); /* Release the FPGA manager */ +fpga_mgr_unlock(mgr); fpga_mgr_put(mgr); /* Deallocate the image info if you're done with it */ |